Method and apparatus for making pinion wire and the like



Oct. 31 1967 o. PAVLOVEC METHOD AND APPARATUS FOR MAKING PINION WIRE AND THE LIKE Filed Jan. 13, 1965 United States Patent 3,349,596 METHOD AND APPARATUS FOR MAKING PINION WIRE AND THE LIKE Oldrich Pavlovec, Brno, Czechoslovakia, assignor to Smeralory Zarody, narodni podnik, Brno, Czechoslovakia Filed Jan. 13, 1965, Ser. No. 425,299 Claims priority, application Czechoslovakia, Jan 16, 1964, PV 259/64 Claims. (Cl. 72-279) ABSTRACT OF THE DISCLOSURE Continuous pinion wire is produced by two sets of pressing tools, a set of sizing tools, and a trimming tool sequentially aligned along the wire path. The wire moves intermittently and the two sets of transversely moving pressing tools respectively start and further shape longitudinally elongated depressions and projections on the stationary wire. The rotary sizing tools and the trimming tool which reciprocates longitudinally of the wire complete shaping of the same.

This invention relates to the shaping of elongated plastically deformable members into elongated bodies of precisely uniform cross section, and more particularly to the making of pinion wire and similar precision shapes.

It is conventional to pass round wire through a plurality of drawing dies arranged in tandem. The dies are arranged gradually to reduce the cross sectional area and to change the cross sectional shape of the wire until wire having the desired cross section is drawn from the last die. The results of the tandem drawing method depend to a substantial extent on the condition of the original wire. Unless exacting metallurgical and chemical controls are maintained during manufacture of the wire, pinion wire satisfying extreme requirements of precision cannot be made by drawing through tandem dies.

It is also known to shape wire by radially applied pressure. It is not possible to convert round wire to pinion wire by radial pressure applied by a single set of tools in a single stage. The process requires progressive application of several sets of differently shaped tools. It is capable of producing pinion wire of high precision.

It is most economical and convenient to handle wire in coils or reels of great length, and to pass it through sequential operations while being unwound from such a coil or reel, the widely spaced ends of each reel being welded or otherwise connected to other reels for an operation which can be made as continuous as is desired. Such a mode of operation is readily possible in wire drawing, but it was not heretofore available in the shaping of pinion wire by radial compressive stresses applied to raw wire, particularly round wire.

Wire may be fed from a coil through a first set of pressing tools in a continuous operation, but it cannot be coiled again after having undergone a preliminary shaping because of the danger of distorting its shape. It has therefore been customary to cut the pre-shaped wire into relatively short straight lengths, and to feed these lengths individually through the work zones in which further shaping operations are being performed.

A primary object of the invention is the provision of a method in which raw wire is converted to precisely shaped pinion wire or similar shapes in continuous length.

Another object is the economical manufacture of pinion wire and the like to very high standards of precision and uniformity.

Yet another object is the provision of apparatus for performing the method.

3,349,596 Patented Oct. 31, 1967 With these and other objects in view, the invention in one of its aspects resides in a method in which several longitudinal sections of an elongated plastically deformable member, such as metal wire, are simultaneously subjected to shaping operations in a plurality of working zones which are spaced along the length of the member, the member being moved stepwise in the direction of its longitudinal axis through the working zones, and the shaping operations being mainly performed while the member stands still.

More specifically, circumferentially spaced portions of each longitudinal section of the member are circumferentiall-y compressed in a first working zone while the member stands still until depressions are formed in the section and projections are raised between the depressions. The aforementioned circumferentially spaced portions are thereafter subjected to further compressive stresses in a second zone until the depressions are deepened. In a third zone, the deepened depressions are sized by rolling contact with tools that further apply compressive stresses, and the excess material of the projections between the depressions may be trimmed off in a fourth working zone, the trimming preferably being done while the member moves longitudinally.

The invention also resides in an apparatus in which two sets of pressing tools are mounted on a support which defines an elongated path for movement of an elongated plastically deformable member. The two sets are arranged for movement toward respective longitudinally spaced portions of the path, and each include a plu rality of tools movable relative to the path in respective directions of movement transverse of the path which are angularly offset from each other relative to the direction of elongation of the path. Actuating means are provided for actuating simultaneous movement of the tools in the afore-mentioned directions.

The apparatus has particular utility in shaping pinion wire from which pinions with more than four teeth are to be made. The making of such wire requires that the directions of movement of the several pressing tools be offset by angles smaller than In order to permit progressive shaping of the depressions and intervening projections of the elongated member by the two sets of pressing tools, the tools of each set are aligned with corresponding tools of the other set for movement in common planes.

The apparatus further comprises sizing tools which are moved along the path of the member to be shaped in the aforementioned planes in timed sequence with the move ment of the pressing tools. The member shaped by the pressing and sizing tools is passed through an opening in a trimming tool which is connected to the sizing tool for joint movement.

Other features of the invention and many of the advantages thereof will be readily appreciated as the same becomes better understood by reference to the following detailed description of a preferred embodiment when considered in connection with the accompanying drawing in which:

FIG. 1 shows a pinion wire shaping device of the invention in side-elevational section on the straight path of the wire through the device;

FIGS. 2 to 4 show details of the device of FIG. 1 on an enlarged scale and in front-elevational section on the lines II-II, III-III, and IV-IV respectively; and

FIG. 5 shows yet another detail of the device of FIG. 1 in front elevation and on the scale of FIGS. 2 to 4.

Referring to the drawing in detail, and initially to FIG. 1, there is seen a cylindrical casing 1 in which the tools of the device are supported. The casing 1 has a stepped cylindrical bore. When considered in axial sequence in the direction of wire movement through the machine, as

indicated by an arrow, the first and third axial portions of the bore have the same diameter and the same length. The interposed second portion is narrower, and the terminal fourth portion is wider than the first and third portions.

A ram 23, dimensioned to pass radially through an opening in the casing 1, engages a double wedge 2 for moving the wedge radially inward in the second portion of the casing bore during a reciprocating movement of the ram 23 indicated by a double arrow. The two faces of the wedge 2 which are obliquely inclined to the axis of the casing 1 cammingly engage corresponding faces of two cylindrical motion transmitting members 3 which are conformingly guided in the second portion of the casing bore for simultaneous axial movement toward and away from the wedge 2 when the latter reciprocates in a radial direction. Aligned axial guide bores in the members 3 communicate through a corresponding wider bore in the wedge 2 in all operative positions of the latter. The radially outward movement of the wedge 2 is actuated by a return spring 20.

The members 3 are the drivers of two almost identical tool sets which are symmetrically arranged relative to the wedge 2 in the first and third portions of the casing bore and differ only by the configuration of respective pressingv jaws 8, 9. Each tool set includes a cylindrical sleeve 4 which is axially guided in the casing 1 and is held in abutting engagement with the associated member 3 by springs 22, as will presently become apparent. The axial bore of each sleeve has a cylindrical portion near the member 3, and a conically flaring portion. Split centering bushings 5, 5' extend from opposite axial sides into the conical bore part. Each of the several jaws 8, 9 is radially guided in corresponding radial grooves of the associated bushings 5, 5 in the conical bore of the sleeve 4.

Tubular plugs 6, 6 are centrally arranged on the bushings 5, 5' and have octagonal heads corresponding to the eight jaws in each set of jaws 8 and 9, and to the eight teeth to be formed in the pinion wire in the illustrated embodiment of the invention. The plugs 6, 6 are held in abutting engagement with the jaws 8, 9 by a helical compression spring 19 interposed in the cylindrical bore of the sleeve 4 between the member 3 and the bushing 5'. A hollow pin 7 is axially slidable in a central bore of the plug 6 and is urged to move inward of the conical bore in the sleeve 4 by a helical compression spring 18 which is coaxial and axially coextensive with the spring 19. The head of the pin 7 tends to move the jaws 8, 9 radially apart.

The centering bushing 5 has a flange near the sleeve 4. A ring 12 is formed with a central recess in which the flange is retained by engaged threads on the bushing and ring. The aforementioned helical springs 22 are interposed between the rings 12 and an externally threaded annular disk 14 and urge the ring 12 axially against the rim of the sleeve 4.

The disk 14 associated with the first tool set in the direction of wire movement forms a centrally apertured end wall for the casing 1 with which it is threadedly connected. The aperture in this disk 14 constitutes the feed opening of the apparatus mounted in and on the casing 1. It is aligned with a feed chuck 24 which permits movement of wire inward of the feed opening, but prevents wire movement in the opposite direction. The chuck which is of a type known in itself, may contain friction rollers which wedgingly engage the wire and an internal wall of the chuck in response to incipient backward wire movement.

The other disk 14 also threadedly engages the casing 1 and separates the third and fourth portions of the axial bore in the casing 1. A sleeve 21 of a third tool set is axially slidable in the fourth casing portion. It has an axial bore which flares conically in the direction of wire movement, and whose narrow end is closed by a threaded plug 27 except for a central aperture. A split centering bushing 25 is arranged in the wide orifice of the conical bore in the sleeve 21. Approximately radial grooves in a face of the bushing 25 fixedly hold respective carriers 11 for eight sizing tools 10. Each tool 10 is a circular disk which is rotatably attached to the associated carrier for movement in a plane which includes the axis of the casing 1. The several disks 10 are angularly spaced about that axis.

The bushing 25 with the disks 10 is held in position in the conical bore of the sleeve 21 by a centrally apertured cap nut 12 whose internal threads engage external threads on the sleeve 21, and by a heavy washer 13 axially interposed between the nut 12' and the bushing 25.

A linkage 26, conventionally indicated by a broken line, connects the sleeve 21 with the ram 23 for synchronized movement. The linkage which may consist of hingedly connected rods, a pinion, and a rack in a manner conventional in itself has not been shown in detail.

A cutting die 16 is retained in a carrier 15 by a guide ring 17, and the carrier 15 is fixedly and coaxially attached to the cap nut 12'.

The afore-described apparatus is operated as follows:

Continuous round wire is introduced axially into the casing 1 initially by hand from a non-illustrated coil or reel through the feed chuck 24, and the prime mover (not shown) which actuates the reciprocating movements of the ram 23 and of the sleeve 21 is started. The jaws 8 of the first tool set and the jaws 9 of the second tool set cammingly engage the associated sleeves 4 and move radially toward and away from innermost positions i1- lustrated respectively in FIGS. 2 and 3.

As is evident from FIG. 2, the jaws 8 form eight shallow axial grooves about the circumference of the Wire, not itself shown in the drawing, and the displaced metal flows under the applied compressive stresses into axially elongated gaps between the jaws to form ridges. The grooves are subsequently deepened, and details of the ridges are pre-shaped between the jaws 9 as is seen from the contours of the jaws in FIG. 3. It is apparent from FIG. 4 that sizing between the disks 10 brings the grooves and the flanks of the ridges to their ultimate shape and dimensions. Passage of the wire through the cutting die 16 causes trimming of excess material from the crests of the ridges. The die 16 together with the guide ring 17 is shown in FIG. 5. The cross sectional shape of the finished pinion wire corresponds to that of the opening in the guide ring 17.

During downward movement of the wedge 2 into the position illustrated in FIG. 1, the sleeves 4 are pushed away from the wedge by the motion transmitting members 3, and drive the jaws 8, 9 radially inward against corresponding portions of the wire which passes through the casing 1. Radial inward movement of the jaws 8, 9 is stopped by the plugs 6, 6' while the pins 7 are pushed back axially against the restraint of the springs 18. The resulting position of the first and second tool sets is shown in the drawing. The plugs 6, 6' thus secure the depth of penetration of the pressing jaws 8, 9, that is the final depth of the depressions and the symmetry of the profile and furthermore the parallelism of the jaws with the axis of the wire being shaped.

When the ram 23 is withdrawn, the spring 20 pushes the wedge 2 upward, and the motion transmitting members 3 are moved toward each other by the expanding springs 19 backed by the springs 22 which also move the sleeves 4 toward each other. The jaws 8, 9 are moved radially apart by the pins 7 under the pressure of the springs 18. When the jaws 8 have separated sufficiently to clear the original cylindrical wire surface, the sleeve 21 with the sizing disks 10 approaches the end of its axial stroke. The wire released by the jaws 8 is entrained by the disks and fed forward a distance which is set to correspond to slightly less than the axial length of the jaws 8 or 9. During the subsequent return movement of the disks 10, the wire is held stationary by the chuck 24. While the disks resume their forward movement, the jaws 8 engage a new portion of the cylindrical wire surface with sufiicient force to prevent axial movement of the wire by the disks 10.

While the sizing disks 10 and the cutting die 16 reciprocate continuously with the ram 23, the ram engages the wedge 2 only, when the ram approaches the lowermost position during its movement inward of the casing -1 illustrated in FIG. 1. During each cycle of ram movement, the wire is fed forward through the casing 1 a distance which is about one-tenth of the stroke of the disks 10 and of the cutting die 16. The dimensions of the finished wire are therefore not affected by spring-back of the metal after working.

The precisely sized wire is pushed through the cutting die 16 in the precise alignment provided by the conforming guide ring 17. It may then be cut into finished lengths convenient for handling, storage, or further processing.

The method of the invention thus combines the handling advantages of wire drawing apparatus employing several dies arranged in tandem with the greater precision, better metal structure, and more economical use of themetal inherent in apparatus which shapes the wire mainly by radially applied compressive stresses.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention, and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of the disclosure which do not constitute departures from the spirit and scope of the invention set forth in the appended claims.

What is claimed is:

1. A method of shaping a continuous elongated plastically deformable member having a longitudinal axis which comprises:

(a) sequentially passing said member in stepwise longitudinal movement through a plurality of working zones;

(b) simultaneously compressing a plurality of circumferentially spaced portions of a first longitudinal section of said member in a first one of said working zones while said member stands still until depressions are formed in said first section, and projections are raised between said depressions;

(c) further compressing said spaced portions of said first section in a second Working zone spaced from said first working zone while said member stands still until said depressions are deepened;

((1) simultaneously compressing a plurality of circumferentially spaced portions of a second longitudinal section of said member in said first working zone while said first section is being compressed in said second working zone until depressions are formed in said second section;

(e) simultaneously sizing said deepened depressions of said first section in a third one of said working zones spaced from said first and second zones while said member stands still;

(f) simultaneously further compressing said circumferentially spaced portions of said second section in said second working zones;

(g) simultaneously compressing a plurality of circumferentially spaced portions of a third longitudinal section of said member in said first Working zone,

(1) said second section being further compressed in said second zone and said third section being compressed in said first zone while the depressions of said first section are being sized in said third zone; and

(h) trimming respective portions of said projections from said first section between said sized depressions in a fourth working zone spaced from said first, second, and third zones, while said first section moves through said fourth working zone. I

2. A method as set forth in claim 1, wherein said portions of said projections are trimmed from said first section While said second section moves from said second to said third zone and said third section moves from said first to said second zone.

3. A method of shaping a continuous wire having a plurality of longitudinally successive sections which comprises:

(a) sequentially passing said sections of said wire stepwise through a plurality of working zones longitudinally spaced along said wire;

(b) simultaneously compressing a plurality of circum ferentially spaced portions of each section in a first one of said working zones while said section stands still until depressions are formed in said portions and projections are raised between said depressions;

(0) further compressing said portions of each section in a second working zone until said depressions are deepened while each section stands still in said second zone;

(d) sizing the deepened depressions of each section in a third working zone while the section stands still in said third zone; and

(e) trimming respective crest portions of said projections from each section while the same moves through a fourth working zone after said sizing of the depressions thereof.

4. In an apparatus for shaping an elongated plastically deformable member, in combination:

(a) support means defining an elongated path for movement of said member;

(b) two sets of pressing tools mounted on said support means for movement toward and away from respective longitudinally spaced portions of said path,

( 1) each set including a plurality of tools movable relative to said path in respective directions of movement transverse of said path and angularly olfset from each other relative to the direction of elongation of the path; and

(c) a plurality of sizing tools mounted on said support means for movement in the direction of elongation of said path in respective ones of said planes, said sizing tools being spaced from said pressing tools in the direction of said path; and

(d) actuating means for actuating simultaneous movement of the tools of said sets toward and away from the respective portions of said path in said directions and for actuating relative movement of said wire and of said sizing tools in timed sequence with the movement of said pressing tools.

5. In an apparatus as set forth in claim 4, said directions being olfset from each other by angles of substantially less than 6. In an apparatus as set forth in claim 4, each tool of each set constituting a pair with a tool of the other set, said tools being elongated in the direction of elongation of said path, said actuating means actuating movement of the tools of each pair in a common plane parallel to said path.

7. In an apparatus as set forth in claim 4, a trimming tool mounted on said support means and connected to said sizing tools for joint movement therewith, said trimming tool being formed with an opening therethrough, and said path extending through said opening.

8. In an apparatus as set forth in claim 4, said actuating means including a wedge member arranged for movement on said supporting means transversely of said path, and having two wedge faces, and two motion transmitting means in camming engagement with said wedge faces respectively and operatively connected to said two sets of pressing tools for actuating said movement thereof.

9. In an apparatus as set forth in claim 4, a pair of plugs mounted near both ends of the pressing tools, said plugs having polygonal heads corresponding to the number of the pressing tools for abutment of said tools against said heads during the inward radial movement of the tools.

10, In an apparatus as set forth in claim 4, said actuating means including a wedge member movable on said support means transversely of said path, two motion transmitting members in abutting engagement with said wedge member and responsive to the transverse movement of said wedge member to move longitudinally of said path in opposite respective directions, and sleeve means interposed between each motion transmitting member and a respective set of pressing tools for moving the tools of the associated set transversely of said path when said motion transmitting member moves longitudinally of said path.

References Cited UNITED STATES PATENTS 737,833 9/1903 Gardner 72402 1,350,634 8/1920 Arnold 72405 1,696,698 12/1928 Sommer 72405 2,139,714 12/1938 Benson 72-405 10 CHARLES W. LANHAM, Primary Examiner.

L. A. LARSON, Assistant Examiner. 

1. A METHOD OF SHAPING A CONTINUOUS ELONGATED PLASTICALLY DEFORMABLE MEMBER HAVING A LONGITUDINAL AXIS WHICH COMPRISES: (A) SEQUENTIALLY PASSING SAID MEMBER IN STEPWISE LONGITUDINAL MOVEMENT THROUGH A PLURALITY OF WORKING ZONES; (B) SIMULTANEOUSLY COMPRESSING A PLURALITY OF CIRCUMFERENTIALLY SPACED PORTIONS OF A FIRST LONGITUDINAL SECTION OF SAID MEMBER IN A FIRST ONE OF SAID WORKING ZONES WHILE SAID MEMBER STANDS STILL UNTIL DEPRESSIONS ARE FORMED IN SAID FIRST SECTION, AND PROJECTIONS ARE RAISED BETWEEN SAID DEPRESSIONS; (C) FURTHER COMPRESSING SAID SPACED PORTIONS OF SAID FIRST SECTION IN A SECOND WORKING ZONE SPACED FROM SAID FIRST WORKING ZONE WHILE SAID MEMBER STANDS STILL UNTIL SAID DEPRESSIONS ARE DEEPENED; (D) SIMULTANEOUSLY COMPRESSING A PLURALITY OF CIRCUMFERENTIALLY SPACED PORTIONS OF A SECOND LONGITUDINAL SECTION OF SAID MEMBER IN SAID FIRST WORKING ZONE WHILE SAID FIRST SECTION IS BEING COMPRESSED IN SAID SECOND WORKING ZONE UNTIL DEPRESSIONS ARE FORMED IN SAID SECOND SECTION; (E) SIMULTANEOUSLY SIZING SAID DEEPENED DEPRESSIONS OF SAID FIRST SECTION IN A THIRD ONE OF SAID WORKING ZONES SPACED FORM SAID FIRST AND SECOND ZONES WHILE SAID MEMBER STANDS STILL; (F) SIMULTANEOUSLY FURTHER COMPRESSING SAID CIRCUMFERENTIALLY SPACED PORTIONS OF SAID SECOND SECTION IN SAID SECOND WORKING ZONES; (G) SIMULTANEOUSLY COMPRESSING A PLURALITY OF CIRCUMFERENTIALLY SPACED PORTIONS OF A THIRD LONGITUDINAL SECTION OF SAID MEMBER IN SAID FIRST WORKING ZONE, (1) SAID SECOND SECTION BEING FURTHER COMPRESSED IN SAID SECOND ZONE AND SAID THIRD SECTION BEING COMPRESSED IN SAID FIRST ZONE WHILE THE DEPRESSIONS OF SAID FIRST SECTION ARE BEING SIZED IN SAID THIRD ZONE; AND (H) TRIMMING RESPECTIVE PORTIONS OF SAID PROJECTIONS FROM SAID FIRST SECTION BETWEEN SAID SIZED DEPRESSIONS IN A FOURTH WORKING ZONE SPACED FROM SAID FIRST, SECOND, AND THIRD ZONES, WHILE SAID FIRST SECTION MOVES THROUGH SAID FOURTH WORKING ZONE. 